Cataracts Flashcards
What is a cataract?
Lens of eye becomes gradually opacified
Coudiness makes it more difficult for light to reach the retina thus casing reduced/blurred vision
Leading cause of blindness
What are risk factors for cataracts?
Normal ageing process genetic Smoking Alcohol excess Sunlight exposure Trauma Radiotherapy DM Long terms torrid use Metabolic disorders HIV+
How do cataract patients present?
Gradual onset of: Reduced vision (painless) Faded colour vision - more difficult to distinguish colours Glare - light appear brighter than usual Halos around lights
Squint, white pupil in children
Nustagmus in infants
What are signs of cataracts?
Defect in the red reflex - cataracts will prevent light from getting to the retina
What investigations in cataracts?
Ophthalmoscopy after pupil dilation - normal optic fundus and optic nerve
Slit lamp examination - visible cataracts
What are the classifications of cataracts?
By lens appearance
Nuclear cataracts - change lens refractive index and noticeable dull colours common in old age
Cortical cataracts: spoke like wedge shaped opacities which have a milder effect on vision
Posterior sub-capsular: progresses faster, cause classic glare from bright lights, from steroid use, just deep to the lens capsule in the visual axis
Dot opacities are common in normal lenses but are seen in fast developing cataracts in DM and myotonic dystrophy
What is non-surgical management of cataracts?
Prescribe stronger glasses
Encourage use fo brighter lighting
Optimise vision but do not slow progression so surgery is required
What is surgical management of cataracts?
Removing the cloudy lens and replacing with an artificial one
Refer if visual impairment is present, impact on QOL, and patient choice, risk/benefits.
Local anaesthesia/general if it is preferred
Ocular biometry mauch be done prior to surgery - measure curvature of the cornea and the length of an eye allowing lens implant prediction.
Provide patient with info on refractive implications of intraocular lens types
After surgery, advise on sue of eyedrops and eye wear, what to do if vision changes and management fo other problems
Achieve 6/12 corrected vision post=op
What are post-op complications?
Posterior capsule thickening - thickening of lens capsule leading to opacification - that with capsulotomy
Astimatism as refraction is corrected
Retinal detachment
Endophthalmitis: inflammation of aqueous or vitreous humour.
How can cataracts be prevented?
Use sunglasses (reduced UVB)
Reduce oxidative stress with antioxidants (vitamin C and caffeine)
Stop smoking
